surface evolver

numerical simulation of static interfaces

The Surface Evolver is an interactive program for the study of static surfaces shaped by surface tension and other energies. By definition it can solve the static Gauss-Laplace-Equation numerically, which determines the pressure difference across the surface. In most cases an analytical solution of the equation cannot be found, because it is an non-linear partial differential equation. The Evolver is the ultimate tool for static and fast solutions. Moreover, graphical output is available as screen graphics and several file formats, including PostScript.

A surface is implemented as a union of triangles, which is predefined by the user in a datafile. The program evolves the initial surface towards minimal energy by a gradient descent method. All defined energies, like surface tension, gravitation, rotation, user-defined energies, can be taking into account.

Contact angles or bounding forces at walls can also be implemented as boundary condition. The Evolver iteration evolves the surface towards the local minimum closest to the initial interface, so global solutions can only found by varying the initial geometry. However, the numerical algorithm can also find critical saddle points.

The program was devolved by the Geometry Center (K.Brakke, University of Minnesota) and is a public available free of charge program.
At the same site you can also find a workshop for beginners from the Trinity College.